Abrasive shoe for rubbing machines



25, 1950 c. D. M CARTHY 2,505,683

ABRASIVE SHOE FOR RUBBING MACHINES Filed May 17, 1946 Patented Apr. 25,1950 ABRASIVE SHOE FOR RUBBING MACHINES Charles D. McCarthy, St. Paul,Minn., assignor to Sundstrand Machine Tool 00., Rockford, 111.,

a corporation of Illinois Application May 17, 1946, Serial No. 670,469

12 Claims. I

This invention relates generally to a clamping device for rubbingmachines and more particularly to an improved construction of suchclamping device for clamping against a rubbing shoe, sheets ofsandpaper, emery cloth or other rubbing material.

Among the objects of my invention are: to provide a novel and improvedclamp device for rubbing machines; to provide a clamping device having acam capable of swinging in both a transverse and longitudinal directionwith relation to a supporting plate; to provide a clamping device havinga clip, and a cam bracket slidable therethrough; to provide a clampdevice having a clip formed with an opening therethrough and a cambracket swingably positioned on a supporting plate and mounted forsliding movement in said opening with relation to said clip; to providea clamp device for rubbing machines and having a swingable clip, and acam bracket and cam member mounted for swinging movement with said clip;and to provide a clamp device easy to manipulate and efficient inoperation for clamping sheets of rubbing material against a rubbingshoe.

Other objects and advantages will become readily apparent from thefollowing detailed description taken in connection with the accompanyingdrawing herein, in which Fig. l is a top plan view of a rubbing shoe andsupporting plate having my improved clamp device mounted thereon, theright hand clamp device being shown closed and the left hand clampdevice being shown open.

Fig. 2 is a longitudinal vertical section on the line 2-2 of Fig. 1.

Fig. 3 is an end elevation looking toward the left hand end of Fig. 2,but omitting the right hand clamp device of Fig. 2 for the sake ofclearness.

Fig. 4 is an end elevation looking toward the right hand end of Fig. 2,but omitting the left hand clamp device of Fig. 2 for the sake ofclearness.

While my invention resides in the combination construction andarrangement of parts illustrated in the accompanying drawings, I havetherein, for illustrative purposes, shown a preferred embodiment and Iwish it understood that the same is susceptible of modification andchange without departing from the spirit and scope of the appendedclaims.

The present invention is an improvement over that shown in the copendingapplication of John B. Hoy, Serial No. 619,360, filed September 29,

1945, for Clamp device for rubbing machines.

In the form shown in the drawings, my improved clamp device ispreferably attached to a supporting plate I of a rubbing machine, saidsupporting plate having mounted on the lower face thereof a rubbing shoe2 of sponge rubber or other suitable yieldable material. The supportingplate I is attached in any suitable manner to a reciprocating member 3of a rubbing machine (not shown). Integrally or otherwise fixed to thesupporting plate I are two pairs of upstanding spaced lugs 4 havingapertures to receive the ends of pins 5, it being understood that thesepins are each mounted between a pair of said lugs 4 as seen in Fig. 1.These clamp devices are arranged one upon each of the opposite ends ofthe supporting plate. As these clamp devices are identically alike,except for the cam levers being reversed in direction of operation, onlyone of these clamp devices will be described in detail.

Clip 6, formed of sheet metal or other suitable material, is provided atits outer end with a flange 1 to serve as a clamping jaw to contact theend portions of the sheets of rubbing material being clamped in thedevice. The inner end of the clip 6 is mounted upon the pin 5 either forrotation thereon, or fixed for rotation therewith as desired. Thismounting of clip 6 upon pin 5 is effected by bending the rear edge ofthe clip into cylindrical form as shown at 8 in Fig. 2.

Clip 6 at its inner edge is formed with a cutaway portion to receive acoil spring ID encircling pin 5, this spring having at one end anextension ll bearing against the upper surface of the supporting plate Iand at its opposite end and extension I2 bearing against the under faceof the upper portion of clip 6. This normally urges the clip to stand inopen position as shown in the left hand side of Fig. 2. Clip 6 is alsoformed in its intermediate portion with a rectangular opening i3, withinwhich is so positioned an upstanding U-shaped cam bracket 14 that theclip may move upwardly and downwardly over said bracket.

This bracket is formed of two upstanding flat side-arms l5 and I6, andits lower end is curved at IT to slidably receive in the bight of theclosed end a pin [8 mounted in openings Ill and 20 extending laterallyfrom the two ends of the larger opening 2| Within which the closed endof the U-shaped cam bracket is positioned.

The upper end of each of the side arms l5 and 16 of the cam bracket isformed with an opening receiving the adjacent end of a pin 22, which pinis also mounted in complementary openings in "the adjacent portion ofthe cam 23. This cam member as viewed in Figs. 2 and 3 has a pair ofangularly extending portions 24, within which at the lower outer endthereof is rotatably mounted a roller 25. The end 2t of the extensions24, on each side of the roller 25, is of a shape to hold the clip inposition when the arm 27 of the cam is swung down; wardly. Positionedbetween the upper surface of the clip 6 and the roller is a bowed leafspring 28 formed as shown in Figs. 1, 3,.and 4. This leaf spring is of alength to contact the side edge portions of the upper surface of theclip with a sliding action when the bowed spring is flexed during theclamping action. It also is formed on each edge with a pair of spacedears 9 to slidably hold the spring in proper position withrelation tothe cam bracket. The roller 2 rollably contacts the upwardly extendingcenter portion 29 of the leaf spring as will be understood from Figs. 3and 4. When the cam gpens as shown in Fig. 3, the pressure will berelieved from the spring and the clip 6 will rise toppen position underaction of the coiled spring Hi. When the cam arm 21 is pushed downwardlyinto closed position as shown in Fig. 4 the spring 28 will be flexed andapply the pres-. sure from the roller 25 against the upper surface ofthe clip to close the clip and tightly grip theadjacent end of the sheetof rubbing material between the clip flange 1 and the top of thesupporting plate l. V Due to the rocking connection between the cambracket l4 and the pin N3 the cam bracket and cam arm 27 will at alltimes occupy planes at right angles transversely of the clip regardlessof whether the clip is being opened or closed. In addition to this rightangular position of the cam bracket and cam arm with relation to theclip, the cam arm will also swing in the arc of a circle laterally withrelation to the supporting plate. It is thus seen that the cam arm has aswinging movement in two different directions, one of these being in aplane longitudinal of the supporting plate, and the other being in aplane transverse of the supporting plate. 7

' To facilitate assembly and ease of construction, the opening 2|,within which the bottom curved end of the cam bracket is seated, extendsvertically, entirelythrough the supporting plate I-. To.provide-for theextending openings l9 and gil within which the ends of the pin l8 aremounted, the supporting plate directly thereabove is provided ith a pairof laterally alined upstanding ,lugs 30 and 3]. These extended openingsopen through the bottom face of the supporting plate and are closed ontheir upper sides by the top portion of the lugs 30 and 3|. The pin I8is loosely mounted therein and there held by the curved lower end of thecam bracket; The cam bracket is held upwardly against pin l8 by the leafspring 28. This construction enables the cam bracket to have a rockingaction with relation to the pin 18 as the clip 6 is opened and closed.For convenience the cam of clip S at one end of the supporting plate isrotated in one lateral direction to tighten the clip with relation tothe supporting plate while the cam at the opposite end of the supportingplate is swung in the opposite lateral direction. To.e nable this, thecamarrns are of right hand and left hand construction.

I claim:

1. A clamp device for rubbing machines comprising a supporting plate, aclip swingably mounted on said plate and having an opening extendingupwardly therethrough, a cam bracket pivotally mounted on the supportingplate about an axis extending laterally of the plate, said cam bracketextending upwardly through the opening in the clip, and a cam pivotallymounted on said cam bracket, the pivotal axis of the cam on the cambracket extending in a direction longitudinally of the supporting plateand the movement of the cam being man are transversely of the plate.

2. A clamp device as claimed in claim 1, in which the cam bracket is aU-shaped metal strip, and a'pin loosely mounted in a recess in saidsupporting plate, the closed end of the U-shaped strip loosely receivingsaid pin, the cam bracket having rocking movement on the pin.

3. A clamp device as claimed in claim 1, in which the cam bracket is aU-shaped metal strip, and a pin loosely mounted in a recess in saidsupporting plate, the closed end of the U-shaped strip loosely receivingsaid pin, the cam bracket having rocking movement on the pin, and abowed leaf spring extending transversely across the top face of the clipand flexingthereagainst as the cam is closed.

4. A clamp device for rubbing machines, comprising, a supporting plate,a clip swingably mounted on said plate, spring means for normally'urging the clip to open positions, said clip havingan opening extendingupwardly therethrough, said plate having an opening extendingtherethrough, said plate opening being in registry with the clipopening, a fulcrum pin removably seated across the plate opening, aU-shaped cam bracket extending through the clip opening and into theplate opening with said pin loosely seated in the closed end of theU-shaped cam bracket, said cam bracket being swingable about saidfulcrum. pin, and a cam pivoted to the free ends of the U-shaped cambracket.

5. A clamp device as claimed in claim 4, having a'bowed leaf springextending transversely across the upper face of the clip and resilientlybearing thereagainst when the cam is closed.

6. A clamp deviceas claimed in claim 4, having a bowed leaf springextending transversely across the upper face of the clip and resilientlybearing thereagainst when the cam is closed, said pin, cam, andcambracket being positioned transversely of the supporting plate wherebythe cam swings sideways of the plate during opening and closing of theclip.

7. A clamp device for rubbing machines, coinprising, a supporting.plate, a clip swingably mounted on said plate, springmeans normally,

urging said clip to open position,.a cam bracket pivotally mounted onsaid plate about an aIXiSEX'r tending laterally of the. plate, saidbracket loosely extending through the clip, and a cam pivotally mountedon said. cam bracket forforcing theclip toward the ,plateas the cam isvswung toclosed position.

.8..A clamp .device as. claimed in claim 7., have ing ,a bowedleafspring extending,transversely' across the topof the clip and positionedbetweenthe clip and the cam, the ends of the bowedsp'ring having slidingengagement 'with the -top. of theclip.

.9. A clamp deviceasclaimed in 'claimfl', the; parts being soarrangedthatthe cam .duri lii pf} eration at all times swings in a paneavn nt 5angles transversely of the clip, the axis of rotation of the cam beingin a plane extending longitudinally of the supporting plate.

10. A clamp device as claimed in claim 7, the parts bein so arrangedthat the cam during operation at all times swings in a plane at rightangles transversely of the clip, said cam bracket during the opening andclosing of the clip swinging with the clip.

11. A clamp device for rubbing machines and the like, comprising, asupporting plate, a clip swingably mounted on said plate, spring meansnormally urging the clip to open position, a cam bracket swingablymounted on the plate about an axis extending laterally of the plate, acam pivotally mounted on the cam bracket about an axis extendinglongitudinally of the plate, a spring between the clip and the cam, saidcam during openin and closing movement of the clip swinging in both alateral and longitudinal direction 20 1,657,342

with relation to the plate.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 687,177 Caldwell Nov. 19, 1901Ayers Jan. 24, 1928

